Glass furnace bubbler patterns



Sept. 24, 1963 B. D. BECK ETAL 3,104,967

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5451/ 0. Beck Arfhur 0. Java/n BY .fi/MW We j ldw United States Patent O3,104,967 GLASS FURNACE BUBBLER PATTERNS Basil D. Beck, Bridgeton,N.L!., and Arthur B. Swain,

Toledo, Ohio, assignors to Owens-Illinois Giass Company, a corporationof Ohio Original application Nov. 13, 1956, Ser. N 621,609, now PatentNo. 2,909,005, dated Oct. 20, 1959. Divided and this application Apr. 1,1959, Ser. No. 803,468

9 Claims. (Cl. 65-178) This invention relates to the efficientutilization of bubblers in a glass furnace, and more particularly to thepatterns of arrangement of these bubblers and a method for providingpatterns of convection currents in the melting zone of a glass meltingfurnace to increase the efficiency and output of production of thefurnace.

This application is a divisional application of copending application,now issued as U.S. Patent No. 2,909,005, dated October 20, 1959.

In this invention it is contemplated to provide a furnace or tank havinginterconnected glass containing compartments separated from each otherby walls and interconnected by a submerged throat passage therebetweenfor the flow of molten glass from one compartment to the other.

Heat is supplied to the glass materials in the compartments of thefurnace to maintain a body of molten glass therein. Within this body ofmolten glass, normal convection currents are present due todifferentials in'temperature and density throughout the glass body.

Also provided is a means for feeding the raw batch materials into themelter and bubbling means provided in the floor of the melter forstirring the molten glass by the formation of gaseous bubbles at thebase of the glass body and causing the bubbles to rise therein. Therising action of the gaseous bubbles within the body of glass can becontrolled by a pattern arrangement to create controlled curtains ofconvention currents which promote a more efiicient melting cycle of thefurnace, improve the quality of glass produced and increase its output.

The bubbles are formed by either a continuous or intermittent typebubbling device. The utility and mode of operation of each of theaforementioned type of bubblers is explained and disclosed in inventionsof J. W. Wright; his U.S. Patent 2,387,222 covering the continuous typebubbler unit, and his U.S. patient entitled, Means of ControllingConvection Currents of Molten Glass, U.S. Patent No. 2,890,548, datedJune 16, 1959, copending herewith, covering the intermittent typebubbler unit.

It has been found in practice that various arrangements or patterns ofplacing the bubblers about the floor of the melter, regardless of thetype of bubble producing unit utilized, produced, generally, increasedefiiciency and output or pull of the glass melter, along with thefollowing specific improved results in the melter derived from suchpatterned arrangement of the bubblers, viz.,

(l) A more uniform homogeneity of the glass is produced,

(2) Certain types of stones such as nepheline and batch, are minimized,

(3) The temperature gradient in the glass body between the floor of themelter and the glass surface is decreased, thereby promoting increasedmelter efliciency,

(4) An increase in temperature of the glass in the refiner is obtainedby increasing the temperature of the glass near the bottom of themelter,

(5) Any color or density separation is prevented from occurring in themelter in the production of colored glasses, such as emerald green andchampagne green glasses,

(6) An increase in the loads is obtained in melting the aforementionedcolored glasses, and

(7) Batch color streak or cord is eliminated in the production oflead-barium glass and borosilicate glass.

These patterns may be more effectively employed by utilizing a pluralityof bubblers in groups of three or more placed closely together in thepattern so that the bubbles emitted from any one such group will assistone another in moving glass as they travel vertically therethrough fromthe floor of the melter to the surface of the molten glass body. In sucharrangement, more pronounced currents are promoted for agitating ormoving the glass. The mentioned groups of bubblers in any pattern may bearranged, for example, as the corners of a triangle, a square, a diamondor along the sides of a parallelogram or like geometric figure.

It is therefore an object of the present invention to provideinstallations of bubblers arranged in patterns along the floor of aglass melter which patterns achieve the aforementioned benefits for aglass furnace.

It is a further object of this invention to provide a method ofadvantageously controlling patterns of convection currents internally ofthe glass body contained in the glass melting zone of a furnace by,subjecting the normal convection currents in said body to a specificpattern of motion influenced by a curtain-like pattern of rising gaseousbubbles within the glass body to obtain the aforementioned benefits fora glass furnace.

It is still a further object of this invention to provide aninstallation of bubblers arranged around the throat outlet of a glassmelter, plus a plurality of staggered transverse rows throughout a majorportion of the remainder of the melting zone of the melter in which theindividual bubblers may be selectively controlled to be made operativeor inoperative, and thereby produce predetermined a-lterable patterns ofrising gaseous bubbles throughout the latter-mentioned transverse rowsof bubblers to obtain the desired control over convection currents inthe body of glass in the melter.

The specific nature of this invention, as well as other objects andadvantages, thereof, will become apparent to those skilled in the artfrom the following detailed description.

In the accompanying drawings:

FIG. 1 is a cutaway perspective view, showing a glass melter providedwith a plurality of intermittent type bubbling units, their bubblingnozzles being arranged about the floor of the melter according to onepattern arrangement of the bubblers employed to illustrate the presentinvention.

FIG. 2 is a partial plan view of FIG. 1 which illustrates the locationof the bubblers according to the present invention.

FIG. 3 is a partial plan view showing a second pattern arrangement ofbubblers employed under the present invention.

In FIG. 1 the lower rectangular portion of a glass melter for containingmolten glass is identified by reference numeral 10, and comprisesadjoining floor 10*, end walls 10 and side Walls 10. Melter 10 issupported by a conventional structure (not shown). The lower portion ofthe melter 10 supports an upper covering structure (not shown) in whichare located opposed firing ports 10 (shown schematically only in FIGS. 2and 3). At one end of melter floor 10 adjacent the central portion ofend wall .10 is located throat outlet 11 which communicates with athroat passage (not shown) leading to the refiner (not shown).

At the opposite end of melter 10 in the upper portion of its end Wall10' are dog houses 13 (shown only schematically in FIG. 3) utilized-forfeeding raw batch materials of a glass composition into melter 10.However,

other means of batch feeding may be utilized with this invention, such:as the overhead center type of batch feeding or blanket batch feedingover the top and along the length of the molten glass body.

Beneath melter floor 10 are interconnected a series of bubbler controlunits 14. These units 14 are each provided with a -bubbler tube 14terminating in a nozzle 14* or 14 inserted into the molten glass bodycontained in the melter and interspersed labout floor 10a in distinctpattern arrangements, which patterns willbe hereinafter described.

Bubbler control units 14 are each connected by conduits 15 to highpressure manifolds 18 and similarly connected by conduits 16 to lowpressure manifolds 17. High pressure manifolds 18 and low pressuremanifolds 17 are connected respectively, to high pressure tank 19 andlow pressure tank 2% Pressure supplied to the bubbler units 14 from thepressure tank 19 is maintained suificiently to explode measured volumesof the pressured gas into the bottom of melter 10 and overcome anypressure head presented by the depth of the glass body over bubblernozzle 14* or 14 The bubbler units shown in FIG. i1, operate to explodeintermittently a series of enlarged gaseous bubbles, as shown anddescribed by the aforementioned US. Patent 2,890,548 of J. W. Wright.

FIG. 2 illustrates the first pattern of the invention and is adaptablealso to a continuous type bubbler system, which is shown and describedin aforementioned US. Patent No. 2,387,222.

Either type bubbler system is an example of a bubble producing devicethat is readily adaptable for use with this invention to produce thegaseous bubbles at the bubbling nozzles. Let it be understood,therefore, that the subject of this invention contemplates thearrangement of bubblers about the melter floor to produce a pattern ofbubbles rising in the molten glass of the melter by any form ofsatisfactory bubble-emitting apparatus. It is the pattern ofdistribution of the bubblers and not the specific bubbler utilized thatfulfills the objects or" this invention.

On the drawings, bubbler nozzles 14* and 140, 140 and 140 of bubblerunits 14 are arranged in various patterns about the melter floor 10 suchthat the bubbles being injected into the glass rise in a chain, oneafter the other, to create movement of the glass in curtainlikepatterns. This curtain like movement of glass is utilized to providecontrolled patterns of convection currents in the melting zone of theglass melting furnace. The contour of these curtains of moving glass isdefined by the particular pattern arrangement of bubblers employed.

Broadly described, each of the patterns shown in the figures comprises afirst array of bubbler nozzles 140, 140 and 149 disposed in asubstantially arcuate arrangement on are A around throat outlet 11 atone end of melter 10, and a second array of bubbler nozzles 14-longitudinally spaced from the first array of said nozzles in thedirection away from the throat outlet 11, wherein the second array ofbubbler nozzles includes, in each case, a plurality of bubblersextending substantially transversely of the melter floor 10 On FIGS. 1and 2 of the drawings, the first array of bubblers is arranged to havethe bubbler nozzles 140, 14%, 146, 14!), 148, 14% and 140 along asubstantially arcuate path A about throat outlet 11. The mentionednozzles are at substantially equal distances from a point on the centerline of the outlet 11. This arcuate arrangement is supplemented byadditional bubblers 14m, 140*, 140" and 140 so as to describe a diamondshaped grouping of bubblers along the side portions of theaforementioned -arc. The two diamond shaped groupings of bubblers areidentifiable on the drawings as bubbler nozzles 140 at the left handside of the furnace floor r (FIG. 2 and bubbler nozzles 140 at the righthand side of the furnace floor Th Bubbler nozzles 14%, and 140 arepaired respectively with bubbler nozzles 140, 144) and 140 to supplementthem in generating motion of the glass vertically at those locations.This first array of bubbler nozzles, when gaseous bubbles are emittedtherefrom, will provide a specific convection cur rent motion in themolten glass at the forward end of the melter equally spaced from thethroat. This provides increased convection current control over themolten glass near the entrance to throat outlet 11.

The arrangement shown in FIG. 1 contains the aforementioned arcuatefirst array of bubbler nozzles around throat outlet 11 and a secondarray comprising a pair of transverse rows of bubbler nozzles 14 spacedfrom each other towards the batch-feeding end of melter 10 near thecentral portion of melter floor 10 These bubbler nozzles may bepositioned in staggered relationship, as shown, or may be in alignedrelationship.

This arrangement of bubblers improves the melting of emerald green andchampagne green glasses to greatly increase the furnace loads of themelter. The increased loads result in reduced stir losses brought aboutby the bubbling action of the second array of bubblers in this pattern,which comprises more than one transverse row of bubblers in thearrangement of said second array. A single row of bubblers is not'suflicient to achieve this result, in that the bubbles are not producedfast enough to prevent the production of seeds in these glasses.

FIG. 3 represents another embodiment of the invention in which thesecond array or bubbler nozzles comprises a pair of transverse rows ofbubblers 14 one transverse row being nearer the outlet end of the melter(throat out- Jet 11) and the other transverse row being adjacent thebatch feeding end of the melter (doghouses 13). The latteramentioned rowserves to assist distribution of batch fed to the surface of the moltenglass body from doghouses 13 in that it keeps the added batch fromsinking too soon after its addition near end wall 10*. The first arrayof bubblers is arranged about throat outlet 11 on either side of an areA, described about the center of outlet 11. In this embodiment thegrouping of bubbler nozzles 140, MW, 149, 140 140 and 144 at thelefthand side of the furnace floor 10 (FIG. 3) and the grouping bubblernozzles 140 140 140, 14%,146 and MW at the right-hand side of thefurnace floor 10 (FIG. 3) are arranged at the sides of parallelogramsthat have their minor diagonal dimension disposed to lie nearly alongthe two end portions of are A. Bubbler nozzles 140 148 and 140 arearranged at the corners of a triangle centered at central portion of areA. Thus, in this embodiment, the first array of bubblers is arrangedabout the throat in an larcuate arrangement (arc A) with theconcentration of bubbler nozzles and accompanying glass moving abilityvarying along that arc. This arrange ment provides for moremotion in theglass near the sides of the furnace through the cooperating effects ofthe bubblers of the parallelogram groups thereat, and a lesser motion inthe glass in the center zone of the melter directly in front of thethroat. The three central bubblers in the triangular grouping (140 liland 140 will cooperate to move a column of glass at that location, but

to a lesser extent than the two groups of bubblers in the parallelogramgroupings in which the bubblers are located more closely together andprovide more cooperation between them in moving the glass thereat. Thetwo latter groupings of bubblers at the ends of arc A will provide moremovement and turbulence in the colder glass near the sides and cornersof the melter. The former group ing or bubblers will provide lessmovement and turbulence by comparison in the hotter glass that isapproaching the throat outlet 11 from the front.

The various patterns of bubbler arrangements of the invention, asdescribed above, contemplate in the main that increased furnacecapacities and results are. achieved by the utilization of bubblerpatterns involving a first array of bubblers spaced substantiallyequally distances from the withdrawal throat and in addition theretomore than one (at least two) spaced rows of bubblers to comprise anygiven configuration or size of geometric pattern in the second array ofbubblers.

The apparatus utilized in the invention is contemplated as being capableof injecting gas into the molten glass body to form bubbles thereinenveloped by molten glass, the bubbles being of a density to steadilyrise so that successive bubbles will produce a steady rising stream ofglass which continuously breaks the surface of the molten glass body.

It will, of course, be understood that various other arrangements of thebubblers may be utilized by mere modifications through a wide range ofform and size to create still further variations from the patterns shownand described herein without departing from the principles of thisinvention. It is, therefore, not the purpose to limit the patent grantedhereon otherwise than necessitated by the scope of the appended claims.

We claim:

1. In a glass melting furnace for continuous production of molten glasscomprising side walls and a bottom wall and having molten glass meltingand fining compartments interconnected by an outlet passage, incombination an arrangement of a plurality of bubble-producing unitsserving in operation to produce rising columns of glass, said units eachincluding a conduit defining an orifice disposed in the molten glass inthe melting compartment below the glass surface, means for supplying gasto said conduit and thereby releasing gaseous bubbles at the orifice ofthe latter, the orifices of said plural units being angularly arrangedabout the bottom wall of said melting compartment such that some of themlie along an arcuate configuration that is disposed in concaverelationship about said outlet passage of said compartment and theorifices of the remainder of said units grouped in close proximity tothe said orifices that are located at the opposite end portions of saidarcuate configuration so that gas issuing from said units forms bubbleswhich produce major agitation in the glass near said ends of the arcuateconfiguration and on either side of said outlet passage.

2. The glass melting furnace defined in claim 1, therein the orifices ofsaid groups are disposed in relation to the orifices describing theopposite end portions of said arcuate configuration to define polygonalgroupings, each being substantially central with respect to said endportions of the arcuate configuration.

3. The glass melting furnace defined in claim 1, Wherein at least oneorifice of said plural units is disposed intermediate said groups oforifices located along the end portions of said arcuate configurationand located in close proximity to said arcuate configuration.

4. The glass melting furnace defined in claim 2, wherein said orificedisposition of each polygonal grouping defines a diamond-shaped figure,two of the orifices at opposite corners thereof being orifices on saidarcuate configuration, and two other orifices at the other oppositecorners thereof lying on opposite sides of said arcuate configuration.

5. The glass melting furnace defined in claim 1, wherein, additionally,three orifices are disposed on either side of said arcuate configurationand intermediate the said groups at the opposite end portions of saidarcuate configuration, said orifices being located as the corners of atriangle.

6. In an apparatus for providing controlled agitation in a workablemolten mass in a glass furnace having interconnected melting and finingareas, said molten mass continuously moving from the melting area to thefining area through an interconnecting passage, a first group of gasintroducing means in the bottom of the molten mass in the melting areaoperable for moving plural columns of glass vertically in said mass,this group of said means being in the bottom of the molten mass andspaced horizontally around the melting area in a substantially angulararrangement that is divergent about said passage, a second group of gasintroducing means in the bottom of the molten mass in the melting areaand arranged with respect to the first group of said means so as to bespaced apart and in the proximity of said first group of said means atthe extremities of said angular arrangement of the latter and operatedfor moving plural columns of glass vertically in said mass, the firstand second groups of said means cooperating to provide a major agitationin the glass mass at said extremities of said angular arrangement and aminor agitation at the glass mass at the intermediate portion of saidangular arrangement.

7. Apparatus for providing controlled currents in a workable molten massin the melting zone of a glass melting furnace wherein glass from saidmass is being continuously withdrawn from said melting zone through athroat passage, comprising means for controlling the convection currentsin said molten mass by subjecting the glass to specific patterns ofmotion generated by a plurality of gas introducing bubbler units incontact with the molten mass to produce rising columns of verticallymoving glass, said patterns of motion being formed by having a portionof the plurality of said units arranged in an angular geometric patternhorizontally disposed about said throat passage, the included angle ofsaid pattern being opposite and outwardly disposed from said passage,there being a greater number of said units at either end portion of saidangular pattern than at the intermediate portion of said pattern,whereby a greater amount of glass agitation is provided at either endportion of said end pattern and at opposite sides of said passage, andthe remainder of the bubbling units arranged to form at least twostraight line rows that are horizontally spaced in said mass from thesaid pattern described by the first-named portion of said plural units.

8. In a glass melting furnace for continuous production of molten glass,said furnace including side walls and a bottom wall and having moltenglass melting and refining compartments that are interconnected by athroat passage, andmeans in said melting compartment for heating theglass, thereby thermally creating convection current agitation, thecombination of means for modifying said convection currents and operableto supplemental motion of the glass comprising a plurality of bubblingmeans serving in operation to cooperate and produce rising fountains ofglass that vary in area, each said bubbling means comprising conduitmeans extending through the bottom wall of the melting compartment anddefining an end orifice that is disposed below the glass surface, meansfor supplying a gas under pressure to the conduit means of each saidbubbling means, said orifices thereof being arranged so that gas issuingtherefrom forms successive bubbles in the molten glass which cooperatewith one another to produce steadily rising movement of the glass whichmeets the surface of said molten glass body, said arrangement of thebubbling means orifices being in the glass in said melting compartmentto define an angular array that is divergently disposed about the throatpassage, there being a greater number of said orifices near each of theend portions of said angular array than at the central portion thereofso as to create a greater rising movement in the glass on either side ofthe throat passage than the rising movement in the glass createddirectly ahead of said throat passage.

9. The glass melting furnace defined in claim 8, wherein the bubblingmeans are grouped in said angular array on either side of said throatpassage in a parallelogram shaped arrangement, at least two orifices ofthe bubbling means of each parallelogram lying along an are describedabout said throat passage, and other bubbling means orifices arranged at'the center of said arcuate array and in front of said nhroat passage,the latter bubbling units being arranged such that they supply a lessermotion to the glass than the said hubbler units on either side of thethroat passage of said parallelogram arrangements.

References Cited in the file of this patent UNITED STATES PATENTS2,331,052 Shadduck Oct. 5, 1943 2,884,744 Monks et a1. May 5, 19592,890,548 Wright June 16, 1959 2,909,005 Beck et al Oct. 20, 1959

8. IN A GLASS MELTING FURNACE FOR CONTINUOUS PRODUCTION OF MOLTEN GLASS,SAID FURNACE INCLUDING SIDE WALLS AND A BOTTOM WALL AND HAVING MOLTENGLASS MELTING AND REFINING COMPARTMENTS THAT ARE INTERCONNECTED BY ATHROAT PASSAGE, AND MEANS IN SAID MELTING COMPARTMENT FOR HEATING THEGLASS, THEREBY THERMALLY CREATING CONVECTION CURRENT AGIATION, THECOMBINATION OF MEANS FOR MODIFYING SAID CONVECTION CURRENTS AND OPERABLETO SUPPLEMENTA MOTION OF THE GLASS COMPRISING A PLURALITY OF BUBBLINGMEANS SERVING IN OPERATION TO COOPERATE SAID PRODUCE RISING FOUNTAINS OFGLASS THAT VARY IN AREA, EACH SAID BUBBLING MEANS COMPRISING CONDUITMEANS EXTENDING THROUGH THE BOTTOM WALL OF THE MELTING COMPARTMENT ANDDEFINING AN END ORIFICE THAT IS DISPOSED BELOW THE GLASS SURFACE, MEANSFOR SUPPLYING A GAS UNDER PRESSURE TO THE CONDUIT MEANS OF EACH SAIDBUBBLING MEANS, SAID ORIFICES THEREOF BEING ARRANGED SO THAT GAS ISSUINGTHEREFROM FORMS SUCCESSIVE BUBBLES IN THE MOLTEN GLASS WHICH COOPERATEWITH ONE ANOTHER TO PRODUCE STEADILY RISING MOVEMENT OF THE GLASS WHICHMEETS THE SURFACEOF SAID MOLTEN GLASS BODY, SAID ARRANGEMENT OF THEBUBBLING MEANS ORIFICES BEING IN THE GLASS IN SAID MELTING COMPARTMENTTO DEFINE AN ANGULAR ARRAY THAT IS DIVERGENTLY DISPOSED ABOUT THE THROATPASSAGE, THERE BEING A GREATER NUMBER OF SAID ORIFICES NEAR EACH OF THEEND PORTIONS OF SAID ANGULAR ARRAY THAN AT THE CENTRAL PORTION THEREOFSO AS TO CREATE A GREATER RISING MOVEMENT IN THE GLASS ON EITHER SIDE OFTHE THROAT PASSAGE THAN THE RISING MOVEMENT IN THE GLASS CREATEDDIRECTLY AHEAD OF SAID THROAT PASSAGE.